1. Technical Field
The disclosure generally relates to voltage converters, and particularly to a voltage converter having a stable output.
2. Description of Related Art
Referring to FIG. 4, a typical voltage converter 90 is used to convert an input voltage V1 to an output voltage V2 for a load.
Referring to FIGS. 4 and 5, the triangular-wave oscillator 4 outputs a sawtooth-waveform voltage V3 to a comparator 5. The feedback circuit 3 outputs a feedback voltage V4 converted from the output voltage V2. The comparator 5 compares the sawtooth-waveform voltage V3 with the feedback voltage V4 and outputs a PWM signal Vp. The output voltage V2 and the input voltage V1 are calculated with the formula V2/V1=D, where D denotes the duty ratio of the PWM signal Vp. Thus, the output voltage V2 can be adjusted by changing the duty ratio of the PWM signal Vp.
However, when a heavy or full load is connected to the voltage converter 90, current output from the voltage converter 90 becomes low, which may pull down the output voltage V2 to be lower than a desired voltage value and has negative influence on the stability of the output voltage V2.
Therefore, there is room for improvement within the art.